BACKGROUND & OBJECTIVE An inability or decreased ability of spermatozoa to bind to the zona pellucida (ZP), an extracellular glycoproteinaceous matrix surrounding egg, is one of the plausible causes of idiopathic infertility. It will be clinically useful to distinguish this condition from other causes of infertility. An assay system, investigating binding of human sperm with ZP glycoprotein may...

Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a specific luminal environment is created by the blood-epididymal barrier; proteins secreted by epididymal principal cells bind to maturing spermatozoa and regulate the maturational proc...

DNA fragmentation is considered an important parameter of semen quality, and of significant value as a predictor of male fertility. Poor quality chromatin is closely associated with, and highly indicative of, some fertility problems. Many methodologies to assess DNA fragmentation in spermatozoa are available, but they are all unable to differentiate between single-stranded DNA breaks (SSB) and ...

The presence of specific messenger RNAs in the nuclei of mature mammalian spermatozoa has been demonstrated by several independent laboratories. Others have suggested that various polymerases may also be active in mature spermatozoa. This has led to the notion that the 'sleeping' genome may not be so quiescent after all. The alternate use of somatic-like nucleosomal and haploid protamine packag...

The mechanisms responsible for mediating the influence of sperm preparation protocols on human sperm function have been investigated. Techniques that involved the separation of motile spermatozoa prior to centrifugation were found to yield sperm suspensions of highest quality. If the spermatozoa were centrifuged prior to isolation of the motile cells, sperm function was impaired. The detrimenta...

Mammalian spermatozoa must undergo a post-ejaculatory period of maturation, known as capacitation, before they can engage in the process of fertilization. Studies in the mouse have established that capacitation facilitates sperm-zona recognition via mechanisms that involve the appearance of tyrosine phosphorylated chaperone proteins on the sperm surface overlying the acrosome, the site of sperm...

The effect of glucose in a modified Ham's F10 medium (MM) without hypoxanthine, phosphate and transition metals on human fertilization and sperm survival in vitro was determined. Mature human oocytes from in-vitro fertilization (IVF) patients or Percoll-washed human spermatozoa were randomly allocated to one of the treatment groups: normal Ham's F10, MM, MM with 5 mM glucose (HGMM) and MM with ...

BACKGROUND Human sperm DNA damage may adversely affect reproductive outcomes, and the spermatozoa of infertile men possess substantially more DNA damage than that of fertile men. To date, there is no available treatment for men with high levels of sperm DNA damage. The objective of this study was to examine the effect of varicocelectomy on sperm DNA denaturation (DD, an index of sperm DNA damag...

Phospholipid hydroperoxide glutathione peroxidase (GPx4) is an intracellular antioxidant enzyme that directly reduces peroxidized phospholipids. GPx4 is strongly expressed in the mitochondria of testis and spermatozoa. We previously found a significant decrease in the expression of GPx4 in spermatozoa from 30% of infertile human males diagnosed with oligoasthenozoospermia (Imai, H., Suzuki, K.,...

The methylation status of human spermatozoa has been examined in relation to the isopycnic density of these cells and their tendency to spontaneously default to an apoptotic state. DNA methylation was evaluated using three independent procedures: high-pressure liquid chromatography, flow cytometry and immunocytochemistry. All three techniques revealed that poor-quality spermatozoa recovered fro...